Improvement in tubular girders and beams



J. JOHNSON...

. TU LAR-Mamas AND BEAMS. 7

No. 192,170, Patented June 19, 1877.

N-FETERS. PHOTD-LITHOGRAPHF-R. WASRIQGTUN, D. C.

PATENT OFFICE.

JOB JOHNSON, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN TUBULAR GIRDERS AND BEAMS.

Specification forming part of Letters Patent No. [92,170, dated June 19,1877 application filed May 23, 1877.

To all whom it may concern:

Be it known that 1, JOB JOHNSON, of Brooklyn, in the county of Kings andState of New York, have invented an Improvement; in Me- 7 tallic TubularGirders or Beams, of which the following is a specification:

This invention is an improvement upon the beam or girder shown inLetters Patent N 0. 184,968, granted to me.

I employ longitudinal tubes placed one above the other, and connected byvertical truss-plates that are recessed to fit the sides of the tubes,and there are longitudinal tiebars at each side of the truss-plates thatserve to connect said truss-plates and retain them in position upon thetubes, and these trussplates are connected at the top or bottom, orboth, by angle-iron bars running longitudinally and forming top andbottom chords to the beam or girder, and at the ends of the girder thereare bearingblocks that connect the tubes, and these feet of the girderare sus-- pended from a cable, as in a bridge, or rest upon columns orpiers.

In the drawing, Figure l is a side elevation of the girder. Fig. 2 is anend View; and Fig. 3 is a cross-section at the line at w.

The tubes at a are of steel or iron, and at their sides are thetruss-plates b b that are recessed to correspond in shape to thetubes aof the truss, and these plates 1) come to gether between the tubes at a,so as to be riveted or bolted together firmly. The same rivets or boltsat c are employed to connect the longitudinal tie-bars c c that are ofiron or steel, and run like webs along at each side of the truss-platesb to connect them together longitudinally, and prevent either of suchplates 11 moving longitudinally of the tubes a.

The truss-plates b b are still" further con nected by the angle-ironbars ff above, and gg below, the tubes, said bars fforming a top chord,and the bars 9 a bottom chord, to the girder. The vertical portions ofthe an gleironbars are riveted or bolted to the trussplates at or neartheir ends.

The bearing-blocks Z are adapted to receive the ends of the tubes a, andof the longitudinal bars 0, the parts being firmly connected by rivetsor bolts, and the top or bottom parts of the end bearing blocks are madewith flanges to form feet that rest upon the supporting columns, piers,or beams, and it is preferable to bolt the parts in place.

The central part of the top chord is under the greatest pressure. "Itherefore prefer to make the angle-iron barsfthe widest or heaviest inthe center, and upon these angle-iron bars the plates 0'0 rest toreceive the ends of transverse beams or girders in cases where the beamor girder shown receives beams or girders for an elevated railway. Theseplates 0 0 are braced by the diagonal bars 0" that connect them to thebottom chord g, which serve to distribute the load upon the girder.

I claim as my invention- 1. The combination, with the tubes at andtruss-plates b, of the angle-iron bars f and g, forming the top andbottom chords of the truss or girder, substantially as set forth.

2. The combination, with the chordsfand 9, tubes a, and trussplates b,of the braces r and plates 0 o, as and for the purposes set forth.

Signed by me this 18th day of May, A, D.

JOB JOHNSON. Witnesses:

GEO. T. PINcKNEY, HAROLD SERRELL.

